Flotation tank



FIG. 1 is a perspective front view of a flotation tank showing our new design;

FIG. 2 is a perspective rear view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a top plan view thereof.

The even broken line showings of the flotation tank in the Figure and the unshaded regions therein are for environmental purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a flotation tank, as shown and described. 